Human circulatory system презентация

The human circulatory system functions like a network of highways. It transports materials around the body.
SOME TRANSPORTED MATERIALS
Oxygen
Carbon dioxide
Digested food
Hormones
Waste chemicals - urea
Heat
Functions of human circulatory system

The Human Circulatory System
It consists of:
HEART
BLOOD VESSELS
BLOOD

The Heart

HEART FACTS:
About 250-340 grams,
In your life time, pumps about 300 million liter of blood,
It contracts about 2.5 billion times.

Main structure of the heart
The heart is made of a special type of muscle called cardiac muscle which contracts and relaxes rhythmically for a lifetime.
The heart is located in the chest cavity and is surrounded by a membrane called the pericardium.
The blood vessels which supply food and oxygen to heart are called as coronary arteries.

External Structure

Internal Structure

Internal Structure Of The Heart
The heart consists of four chambers :
The two upper chambers = ATRIA
The two lower chambers = VENTRICLES
Between atria and ventricle there are valves, preventing the blood coming back to the atria when the ventricles contract.
The valve on the left is BICUSPID VALVE
The valve on the right is TRICUSPID VALVE
The lub-dub heart sound is generated by valves.

VALVES

Semilunar Valves
Semilunar valves are found between the arteries and the ventricles.
They prevent the blood entering the arteries when the ventricle contract.
Between left ventricle and aorta there is aortic valve
Between right ventricle and pulmonary artery there is pulmonary valve

VALVES

C
A
R
D
I
A
C
C
Y
C
L
E

The heart pumps blood into the body.
Relaxation of heart is known as diastole.
Contraction of heart is known as systole.
Blood is pumped into the ventricles by atrial contraction, and blood is pumped into the vessels by ventricular contraction.
Cardiac activity

Heartbeat is controlled by autonomic nervous system.
The autonomic nervous system stimulates the sinoatrial node and atrioventricular node for initiation of a contraction. The atria and ventricles contract as a result.
SA node sends impulses to heart every 0.85 seconds
Control of HEART

Heart Rate
Parasympathetic nerves reduces the heart rate.
Sympathetic nervs speed up the heart rate.
Acetylcholine reduces the heart rate.
Adrenaline speed up the heart rate.
CO2 reduces the heart rate.
High temperature increases the heart rate.

BLOOD VESSELS
There are 3 types of vessels in our body.
These are;
ARTERIES
VEINS
CAPILLARIES

1. Arteries
Arteries carry blood away from heart to the different tissues of the body.
Artery walls are stronger and thicker and more elastic than the veins.
The pulse is the rhythmic contraction and relaxation of arteries which are parallel to the contraction of the heart.
Branches of arteries are called as arteriole.
They carry mainly oxygenated blood

2. Veins
Veins carry blood to heart
Their walls are much thinner than the walls of arteries.
Veins are farther from the heart and exposed to lower pressures.
Veins are larger in diameter than arteries.
Most veins have one-way valves. A valve is a flap of tissue that ensures blood passes through but does not flow backwards.
Branches of veins are called as venules
Veins mainly carry deoxygenated blood

3. Capillaries
Capillary walls are only one cell thick. Gas and nutrient molecules pass easily through their thin walls.
They are non-muscular in structure.
Capillaries connect arteries to the veins.

artery
vein
arteriole
venule
capillary

Blood Pressure
Blood exerts pressure on the walls of vessels during circulation
Blood pressure increases when the ventricles contract (systole) and decreases when the ventricles relax (diastole)
In normal healthy human systolic pressure is 120 mm Hg and diastolic is 70 mm Hg (120/70)
The blood pressure increases during physical work, and decreases during rest and sleep
Abnormal increase of blood pressure is known as hypertension
Abnormal decrease – hypotension

Measuring Blood Pressure

Blood Circulation
There two types of circulation in human body:
1. Pulmonary Circulation: Oxygen poor blood is pumped into lungs. And oxygen rich one is brought back to the heart.
2. Systemic Circulation: Oxygen rich blood is pumped into body parts. And contaminated blood is brought back to the lungs.

Pulmonary
circulation
Systemic
circulation

Blood Movement
Left ventricle pumps oxygenated blood to body, that’s why it’s walls are thicker
Right ventricle pumps deoxygenated blood to lungs
All arteries except pulmonary artery carry oxygenated blood
All veins except pulmonary vein carry deoxygenated blood

Internal Structure

BLOOD
Blood is a type of tissue that formed by mesoderm layer of embryo. An adult Human body has approximately 5,5 liters of blood.

FUNCTIONS OF BLOOD
Transport of materials
Hormone transport
Homeostasis
Immune response
Blood Clotting

BLOOD COMPONENTS
Blood contain 2 main parts. These are:
Blood Plasma
Blood cells

Blood Plasma
Plasma is liquid part of blood. It includes water (90%) and dissolved proteins. It also contains salts, glucose, aminoacids, fatty acids, vitamins, hormones and cellular wastes.

Blood Cells
There are three types of blood cells:
Erythrocytes (=Red Blood Cells)
Leucocytes (=White Blood Cells)
Thrombocytes (=Platelets)

There are approximately 5 to 5,5 million of erythrocytes per cubic millimeter of blood.
The major function of erythrocytes is to transport oxygen from lungs to tissues and transport CO2 from body tissues to lungs.
ERYTHROCYTES

Mammalian erythrocytes have no nucleus at adult (maturation) stage.
They are produced by red bone marrow.
Erythrocytes live(!) for 120 days
Erythrocytes are broken down by Reticulo-Endothelial System in spleen, liver and lymph nodes.

HEMOGLOBIN
Erythrocytes are filled with hemoglobin.
Hemoglobin is iron (Fe) containing pigment.
It gives red color to blood.
Hemoglobin carries oxygen.
Erythrocytes live(!) for 120 days

LEUCOCYTES
Leucocytes protect the body from infections.
They are produced by red bone marrow and lymph nodes.
They can move through the tissue.

Normally there are only 6000 to 8000 leucocytes per cubic millimeter of blood. When there is an infection in the body, number of leucocytes may increase to 30000 per cubic millimeter.

PLATELETS
Platelets are produced by bone marrow.
They play major role in blood clotting.
Blood clotting is the solidification of blood in order to stop bleeding.

THE MECHANISM OF BLOOD CLOTTING
Prothrombin (In liver)
Vitamin K
Thrombogen
Thrombocytes + O2
Thrombokinase
Thrombin
Fibrinogen Ca ions
Platelets + Fibrin
Cloth

Diseases related to circulatory system
Anemia
Leukemia
Arteriosclerosis

Anemia

Arteriosclerosis
When blood vessels become narrow and lose their elasticity
Fats and Ca++ ions adhere to the walls of blood vessels, and by this stroke and heart attack may occur
This disease occurs as a result of eating disorders
Is seen mainly in men and women over the age 40

Heart attack, infarcts